SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '546f9413a2fb928725d96fb8ce935727a10a1514f2c7f1563c2692007a8b268a' 
  AND token = 'hptJVOEAn7uneB2UJFAARcvUzoANji67TSc+6X3fTCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}